package server;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * @author lubiao
 * @date 2021/5/5
 * @desc
 */
public class StaticResourceUtil {

    /**
     * 获取静态资源的绝对路径
     * @param path
     * @return
     */
    public static String getAbsolutePath(String path){
        String absolutePath = StaticResourceUtil.class.getResource("/").getPath();
        return absolutePath.replaceAll("\\\\","/") + path;
    }

    /**
     * 读取静态资源⽂件，通过输出流输出静态资源
     * @param inputStream
     * @param outputStream
     */
    public static void outputStaticResource(InputStream inputStream, OutputStream outputStream) throws IOException {

        int count = 0;
        while(count == 0){
            count = inputStream.available();
        }
        int resourceSize = count;
        //输出http请求头，在输出http请求内容
        outputStream.write(HttpProtocolUtil.getHttpHeader200(resourceSize).getBytes());

        long written = 0;//已读取的大小
        int byteSize = 1024;//计划每次缓冲的大小
        byte[] bytes = new byte[byteSize];

        while(written < resourceSize){
            if(written + byteSize > resourceSize){ // 说明剩余未读取⼤⼩不⾜⼀个1024⻓度，那就按真实⻓度处理
                byteSize = (int) (resourceSize - written);// 剩余的⽂件内容⻓度
                bytes = new byte[byteSize];
            }
            inputStream.read(bytes);
            outputStream.write(bytes);

            outputStream.flush();
            written += byteSize;
        }
    }
}
